I just brought home my new 2005 YFZ450LE and have a stack of parts to put on. I plan on moving the exhaust cam 1 tooth, installing the Yoshi comp full exhaust and adding the Woods intake with K&N in the airbox with the lid off. I live on the coast in Florida and the temps here are from the mid 70s to mid 80s right now. Where should I start with the Jetting? What brand jets should I use? Is there really a performance difference between Dyno Jet and GYT-R jets? Will adding an aftermarket CDI require the jetting to be changed? Thank you all in advance for your help.

 

Check out Daddog web site, they have alot of good jetting info....Good luck

You could do a search on yfz jetting on the Yamaha form, lots of jetting info right here!!!!!!!

 

You asked where you should start jetting? I would suggest about 500 miles north, away from the Hurricanes! HAAAAAAAAAAAA

Just kidding, I'd agree with bigdaddy on daddogs jetting page. Good luck

 

I agree about the Dogriders! Awesome info!

As far as baseline, I would think a good ballpark guess would be a 170 main, 45-48 pilot, stock needle on 5th clip position, and fuel screw aroung 2 turns out.
That should get you pretty dang close with those mods!

Personally, I don't see a reason to use any other jets than the standard Keihin jets. They can be reference easier than some of the aftermarket ones also.

I have the stock needle still in mine on the 5th clip position, and there is room for another adjustment on it (to go richer if you need to).